High speed non-contact transport of small object in air through ultrasonic traveling field excited with parallel vibration plates

In precision manufacturing industry and pharmaceutical field, a method to manipulate micro parts and drugs without contact has become one of the key technologies. It is well known that particles can be trapped at the nodal points of acoustic standing waves if the particles are much smaller than the wavelength of the standing wave. In this paper, we have introduced a new configuration of the vibration system for generating traveling ultrasonic fields and succeeded in the non-contact transport of polystyrene sphere. The waveguide was composed of two parallel flexural vibration plates with a position shift of a quarter wavelength. The sphere was levitated at the nodal position of the vertical standing wave in the waveguide and transported by the traveling wave component in the horizontal direction. The transportation distance and speed were 40~50 mm and 293~543 mm/s, respectively.